Differently from a voltage driving manner for conventional Liquid Crystal Display (LCD) devices, Organic Light-Emitting Diode (OLED) devices are driven by a current, and therefore, in a pixel circuit where each OLED device is located, in addition to a current-driven control switch, there is also a need for an addressing switch for writing a data voltage. Conventionally, the addressing switch is implemented by a Thin Film Transistor (TFT). Thus, a scanning line is required to supply a scanning signal to a gate of a TFT of each addressing switch. As a result, when input impedance of a pixel circuit in an input position of the scanning signal is not large enough, amplitude of a voltage of the scanning signal may be degraded partly after the scanning signal passes through a pixel circuit, which easily causes a pixel circuit at the end of the scanning line not to be able to receive the scanning signal and therefore not to be able to normally supply a driving current, resulting in poor display.